* src/gmalloc.c (min): Delete duplicate macro.  We import lisp.h
unconditionally, so it is always defined here.

Run "TZ=UTC0 admin/update-copyright".

This is brittle, as evinced by the recent problem with lib/stdlib.c.
* src/conf_post.h: Move potential inclusion of stdlib.h and
redefinitions of malloc, free, realloc, aligned_alloc, and calloc
from here ...
* src/lisp.h: ... to here.  Do not redefine the symbols
if UNEXMACOS_C is defined.
* src/unexmacosx.c: Do not undef malloc, realloc, free.
(UNEXMACOS_C): New symbol, to prevent lisp.h from defining them.

* src/gmalloc.c (gdefault_morecore): Remove HYBRID_MALLOC code.
(allocated_via_gmalloc, hybrid_malloc, hybrid_calloc, hybrid_free_1)
(hybrid_free, hybrid_aligned_alloc, hybrid_realloc): Remove functions.

* msdos/sed1v2.inp:
* msdos/sedlibmk.inp:
* src/alloc.c (GC_MALLOC_CHECK, USE_ALIGNED_ALLOC)
(refill_memory_reserve, aligned_alloc):
* src/emacs.c (main):
* src/lastfile.c (my_edata):
* src/lisp.h:
* src/ralloc.c:
* src/sysdep.c (get_current_dir_name_or_unreachable):
* src/xdisp.c (decode_mode_spec): Remove HYBRID_MALLOC conditions.

* configure.ac (hybrid_malloc, HYBRID_MALLOC): Remove variables and
dependent code.
* src/conf_post.h (hybrid_malloc, hybrid_calloc, hybrid_free)
(hybrid_aligned_alloc, hybrid_realloc): Remove conditional prototypes.
* src/Makefile.in (HYBRID_MALLOC): Remove variable.
(base_obj): Remove sheap.o
(LIBEGNU_ARCHIVE):
* lib/Makefile.in (libgnu_a_OBJECTS): Remove libegnu.a support.

* src/gmalloc.c (__malloc_initialize_hook): Also declare in
advance on Glibc 2.24 and later.
(__after_morecore_hook, __morecore): Likewise on Glibc 2.34 and
later.

* src/gmalloc.c (hybrid_free_1): New function, with the body of
the previous 'hybrid_free'.
(hybrid_free): Call 'hybrid_free_1' while preserving the value of
'errno'.  Suggested by Paul Eggert <eggert@cs.ucla.edu>.